I would guess that Ada is simply more known. Keep in mind that tech exploded in the past ~3.5 decades whereas those languages are much older and lost the popularity contest. If you ask most people about older languages, the replies other than the obvious C and (kind of wrong but well) C++ are getting thin really quickly. COBOL, Ada, Fortran, and Lisp are probably what people are aware of the most, but other than that?
You've forgotten about BASIC, SNOBOL, APL, Forth, and PL/1. There were many interesting programming languages back then. Good times!
The first five languages I learned back in the 70s: FORTRAN, Pascal, PL/I, SNOBOL, APL. Then I was an Ada and Icon programmer in the 80s. In the 90s, it was C/C++ and I just never had the enthusiasm for it.
Icon (which came from SNOBOL) is one of the few programming languages I consider to embody truly new ideas. (Lisp, Forth, and Prolog are others that come to mind.)
Icon is an amazing language and I wish it was better known.
You probably know this but, for anyone else who is interested, the easiest way to get a feel for Icon nowadays may be through its descendant Unicon which is available at unicon.org.
I found Pascal more readable as a budding programmer. Later on, C's ability to just get out of the way to program what I wanted trumped the Pascal's verbosity and opinionatedness.
I admit that the terseness of the syntax of C can be off-putting. Still, it's just syntax, I am sorry you were disuaded by it.
True.
I dabbled in some of them during some periods when I took a break from work. And also some, during work, in my free time at home.
Pike, ElastiC (not a typo), Icon, Rebol (and later Red), Forth, Lisp, and a few others that I don't remember now.
Not all of those are from the same period, either.
Heck, I can even include Python and Ruby in the list, because I started using them (at different times, with Python being first) much before they became popular.